Downstream from Arunachal Pradesh the river becomes wider and at this point is called the Siang. After reaching Assam, the river is known as Brahmaputra. From Assam, the river enters Bangladesh at Ramnabazar. From there until about 200 years ago it used to flow eastward and joined the Meghna River near Bhairab Upazila. This old channel has been gradually dying now. At present the main channel of the river is called Jamuna River, which flows southward to meet Ganges, which in Bangladesh is called the Padma.

When leaving the Tibetan Plateau, the Yarlung River flows in the world's largest and deepest canyon, Yarlung Tsangpo Grand Canyon.[1] The gorge has been described as "the highest river in the world" by the organizers of a kayaking expedition, although it's not clear from their press release what definition was used. [2]

The Yarlung Tsangpo River is the highest major river in the world. Its longest tributary is the Nyang River. In Tibet the river flows through the South Tibet Valley, which is approximately 1,200 kilometres (750 mi) long and 300 kilometres (190 mi) wide. The valley descends from 4,500 metres (14,800 ft) above sea level to 3,000 metres (9,800 ft).[3][4] As it descends, the surrounding vegetation changes from cold desert to arid steppe to deciduous scrub vegetation. It ultimately changes into a conifer and rhododendron forest. The tree line is approximately 3,200 metres (10,500 ft).[5]Sedimentary sandstone rocks found near the Tibetan capital of Lhasa contain grains of magnetic minerals that record the Earth's alternating magnetic field current.[6]

The Yarlung Tsangpo River has three major waterfalls.[9] The largest waterfall of the river, the "Hidden Falls", was not publicized in the West until 1998, when its sighting by Westerners was briefly hailed as a "discovery."[10] They were even portrayed as the discovery of the great falls which had been the topic of stories told to early Westerners by Tibetan hunters and Buddhist monks, but which had never been found by Western explorers at the time.[11] Chinese authorities protested, however, saying that Chinese geographers, who had explored the gorge since 1973, had already taken pictures of the falls in 1987 from a helicopter.[12]

Since the 1990s the Yarlung Tsangpo River has been the destination of a number of teams that engage in exploration and whitewater kayaking. The river has been called the “Everest of Rivers” because of the extreme conditions of the river.[8] The first attempt to run was made in 1993 by a Japanese group who lost one member on the river.

In January–February, 2002, an international group consisting of Scott Lindgren, Steve Fisher, Mike Abbott, Allan Ellard, Dustin Knapp, and Johnnie and Willie Kern, completed the first descent of the upper Tsangpo gorge section.[14]

^"Outside Online Archives". outside.away.com. Retrieved 2009-07-19.. Quote: "The Tsangpo Gorge is the highest river in the world and it has stood as one of the last unattained adventure prizes left on earth, until now."